Skip to content
Percona Software for MongoDB Documentation

Get free database assistance or contact our experts for personalized support.

Get help from Percona

Backups in sharded clusters

For PBM v1.0 (only)

Before running pbm backup on a cluster, stop the balancer.

In sharded clusters, one of the pbm-agent processes for every shard and the config server replica set writes backup snapshots into the remote backup storage directly. For logical backups, pbm-agents also write oplog slices. To learn more about oplog slicing, see Point-in-Time Recovery.

The mongos nodes are not involved in the backup process.

The following diagram illustrates the backup flow.

image

Important

If you reshard a collection in MongoDB 5.0 and higher versions or unshard a collection in MongoDB 8.0 and higher versions, make a fresh backup to prevent data inconsistency and restore failure.

Last update: October 7, 2025
Created: October 7, 2025